The present invention relates to a terminal mechanism, such as a copier and printer, and more specifically to a sheet post-processing device which includes means for post-processing, such as stapling or punching, with respect to prints, such as documents.
In case prints formed by an image forming device such as a printer or a copier are automatically stapled to provide a set of the sheets, after aligning end sides of sheets successively stacked on a process tray for temporarily stacking the sheets in order to operate this process, the sheets are stapled by stapling means. This stapled set of the sheets is transferred to another stacking tray to be stacked thereon, and after stacking further sheets, stapling the set of the sheets continues to be operated. At this time, there is a demand that the following set of the sheets is apparently distinguished from the preceding set of the sheets by carrying out a jog operation to shift the following set of the sheets from the preceding set of sheets. Conventionally, to achieve the above object, a jog operation has been achieved by changing a central position of aligning means, which aligns the sheet in the width direction for operating a post-process.
However, for example, in case of performing the jog operation sheet by sheet, since the jog operation can be started only when the sheet lands on the process tray, this landing time deteriorates productivity of the sheet post-processing device. Or, even when the post-process including the jog operation is not necessary, this landing time has to be wasted. Actually, although this period of time is one second or less, need of the image forming device for improving productivity by reducing intervals of the sheets to the limit should not be impaired.
An object of the present invention is to propose an embodiment in which productivity of ejecting sheets onto a stacking tray without post-processing is improved by providing a guide in a sheet transfer path, and which can perform a jog operation.